DESCRIPTION (adapted from applicant(s abstract): Statement of the problem: Mortality of patients with pulmonary contusions is 10-25%, with higher morbidity, and over two thirds of patients presenting to the emergency room for surgery have sustained a pulmonary contusion. Additionally, pulmonary contusion involves different outcomes in children and older adults. Yet, even in normal adults pulmonary contusion is clinically and biomechanically one of the least well understood injuries resulting from blunt trauma. [unreadable] [unreadable] Methods: The study population is Male Wistar rats, for which a pulmonary [unreadable] contusion injury model exists but is not well developed. Data from a multidisciplinary team gathering clinical and biological data relating to pulmonary contusion, as well as new engineering data will be used to answer the hypotheses in the Specific Aims. [unreadable] Aim 1: Control pulmonary contusion in the lung. Hypothesis: Contusion injury can be controlled in terms of volume of contused lung and severity of injury. Aim 2: Quantitate pulmonary contusion in the lung. Hypothesis: Volume and severity of lung injury can be positively correlated to input energy. Aim 3: Formulate finite element injury metrics of pulmonary contusion. Hypothesis: A finite element-based injury metric relating stress and strain to input energy is reflective of contused volume and severity of injury. [unreadable] [unreadable] Implications for prevention: Biomechanically, the model can be used to develop interventions to protect motor vehicle occupants, children involved in falls, etc. from sustaining a pulmonary contusion. Clinically, the model can be used to evaluate treatment strategies for the acute care setting. The research is innovative in its multidisciplinary approach: it adds biomechanics to clinical and basic science research, allowing quantifiable control and measurement of pulmonary contusion injury which has not been previously achieved. It is made possible by combining modern instrumentation and state of the art biomechanical computer codes with basic injury research at the institution performed by clinicians. [unreadable] [unreadable]